Neural activity in the gamma frequency range (30 Hz or greater) has been hypothesized to reflect the synchronization of neural assemblies involved in binding or integration of various features of an object. Gamma range synchronization is thought to depend on inhibitory GABAergic circuits, which have been implicated in schizophrenia. This project will investigate whether auditory neural circuits can support gamma range synchronization in schizophrenia, or in schizotypal personality disorder. Schizotypal personality disorder is genetically and symptomatically related to SZ, but without the complicating variables present in a chronic psychotic disorder, such as long-term medication, hospitalization, and lifestyle changes. Gamma range synchronization will be evaluated by entraining the electroencephalogram to different frequencies of periodic auditory stimulation. Since deficits in gamma range synchronization may underlie a variety of information processing disturbances, the relationship among gamma range synchronization deficits, clinical symptoms and intellectual performance will also be evaluated. These data may identify disturbances in oscillatory mechanisms in schizophrenia spectrum disorders, and develop novel techniques to non-invasively probe neural circuits in brain dysfunction.